Open a new tab

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations only declare readOnlyHint=false, so the description is the sole source of behavior. It usefully discloses that a new context id is returned, but omits key traits: whether the new tab becomes focused/active, whether navigation is awaited before returning, and whether the prior tab state is affected.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

Two short sentences, purpose first and return value second, with no filler. Nothing could be removed without losing information.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no output schema, the description correctly covers the return value (new context id). For a tool that mutates browser state and feeds into later tools by id, it should also say whether the tab is foregrounded and how the id relates to browser_list_tabs/browser_activate_tab.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% and there is a single optional URL parameter already documented. The description's "optionally navigating it to a URL" adds only emphasis, not format or default behavior detail beyond the schema.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

Specific verb+resource ("Open a new tab") with the optional navigation and a stated return value. It does not differentiate itself from close siblings such as browser_navigate or browser_duplicate_tab, which an agent could plausibly confuse it with.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

There is no statement of when to use this versus browser_navigate (open a tab and load a URL in one call) or browser_duplicate_tab / browser_reopen_closed_tab. The agent must infer selection from the name alone.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.